Cooling fan

ABSTRACT

A cooling fan with high heat-dissipating performance includes a plurality of blades; and a frame for receiving the blades therein, wherein the frame has a reduced height for exposing the blades to outside of the frame so as to allow air to enter into the frame via a top portion and a peripheral portion of the blades to improve air introduction and heat dissipating efficiency of the cooling fan. A cover may be mounted to a top surface of the frame, and formed with a plurality of openings for allowing air to enter into the frame through the openings; such an arrangement cam effectively enhance air intake and working efficiency of the cooling fan.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. application Ser.No. 11/332,397, filed Jan. 17, 2006, which is a continuation applicationof U.S. application Ser. No. 10/339,472, filed Jan. 9, 2003, whichclaims priority to Taiwan application 91205935, filed Apr. 30, 2002, nowissued. The entire disclosures of all the above applications are herebyincorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates to cooling fans, and more particularly, toa cooling fan for dissipating heat produced by internal elements of acomputer, wherein a frame of the cooling fan for receiving blades isformed with a reduced height to increase air introduction area and thusto enhance working efficiency of the cooling fan.

BACKGROUND OF THE INVENTION

As electronic and information industries prosperously develop, variouskinds of electronic products with different appearances and functionsare introduced into the market. For example, a central processing unit(CPU) of computer may be formed with chips operating at a high speed upto 1-2 GHz, and such high-speed operation would lead to accumulation ofheat produced from electric currents by effect of resistance in the CPU.Therefore, the computer is mostly mounted with a heat-dissipatingdevice, so as to confine operation of the CPU within a certain range oftemperature and to prevent the chips from being damaged by over-heatthat may cause failure of the entire computer.

FIGS. 1A and 1B illustrate a conventional cooling fan 100 fordissipating heat produced by chips of a CPU. This cooling fan 100includes a frame 101 adapted to be screwed to heat sinks (not shown),and a plurality of blades 103 disposed in and enclosed by the frame 101and connected to a power output shaft of a motor 102. The motor 102drives the blades 103 to rotate and thereby suck or exhaust air into orout of the frame 101 to create airflow effect. When air is directedtoward the heat sinks, it takes heat away from the heat sinks and thuscools the chips of the CPU. The cooling fan 100 is formed with an airinlet for introducing air into the frame 101, as shown in FIG. 1B, theair inlet is a top opening of the cooling fan 100 for exposing theblades 103. As such, if a block is situated closely in front of the airinlet, it would impede movement of air and adversely affect airfloweffect for the blades 103.

Moreover, in response to profile miniaturization of electronic products,a computer is provided with limited internal space for receiving areduced-sized cooling fan connected to heat sinks. As a result, thecooling fan may be located very close to a housing of the computer,which reduces air introduction area and space/distance for generatingairflow effect, and thereby leads to poor heat dissipation for thecomputer.

Therefore, the problem to be solved herein is to provide a cooling fanwith enhanced cooling effect for use in a limited-sized computer.

SUMMARY OF THE INVENTION

A primary objective of the present invention is to provide a cooling fanfor use in a decreasingly sized computer, wherein the cooling fan isadapted to have increased air introduction area to enhance coolingperformance thereof.

Another objective of the invention is to provide a cooling fan, whereina frame of the cooling fan is formed with a reduced height so as toincrease air introduction area and airflow effect for the cooling fan.

A further objective of the invention is to provide a cooling fan, forallowing air to be smoothly introduced into operative part of acomputer, so as to conduct good heat dissipation and help prolonglifetime of the computer.

To achieve the above and other objectives, the present inventionproposes a cooling fan including a plurality of blades; and a frame forreceiving the blades therein, wherein the frame has a reduced height forexposing the blades to outside of the frame so as to allow air to enterinto the frame via a top portion and a peripheral portion of the bladesto thereby improve air introduction and heat dissipating efficiency ofthe cooling fan.

The above cooling fan may further include a cover mounted on a topsurface of the frame. The cover serves as a protective shield to preventan operator from being in contact with or injured by the blades duringmaintaining or repairing a computer. The cover may be formed with aplurality of openings for allowing air to enter into the frame throughthe openings, and thereby helps enhance air intake and workingefficiency of the cooling fan.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be more fully understood by reading thefollowing detailed description of the preferred embodiments, withreference made to the accompanying drawings wherein:

FIG. 1A (PRIOR ART) is a perspective view of a conventional cooling fan;

FIG. 1B (PRIOR ART) is a cross-sectional view of the cooling fan shownin FIG. 1A taken along line A-A;

FIG. 2A is a perspective view of a cooling fan according to a firstembodiment of the invention;

FIG. 2B is a sectional view of the cooling fan shown in FIG. 2A takenalong line B-B;

FIG. 3 is a perspective view of the cooling fan according to a secondembodiment of the invention;

FIG. 4 is a perspective view of the cooling fan according to a thirdembodiment of the invention;

FIGS. 5A and 5B are respectively perspective views of the cooling fanaccording to a fourth embodiment of the invention;

FIG. 6 is a perspective view of the cooling fan according to a fifthembodiment of the invention;

FIG. 7 is a perspective view of the cooling fan according to a sixthembodiment of the invention; and

FIG. 8 is a perspective view of the cooling fan according to a seventhembodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description is made with reference to FIGS. 2-7 fordepicting preferred embodiments of a cooling fan provided in the presentinvention.

FIGS. 2A and 2B illustrate a cooling fan 200 according to a firstembodiment of the invention. As shown in the drawings, the cooling fan200 includes a plurality of blades 203 connected to and driven by adriving means such as a motor 202 to rotate and thereby suck in orexhaust air to create airflow effect; and a frame 201 formed with areduced height to increase air introduction area and receiving theblades 203, wherein a plurality of through holes 201 a are peripherallyformed on the frame 201 and can be engaged with mounting screws (notshown) for connecting the cooling fan 200 to a heat sink (not shown)conventionally used in a computer.

The frame 201 is reduced in height by a distance h from the top of thecooling fan 200 in a manner as to increase contact area between theblades 203 received within the frame 201 (especially the outer peripheryof the blades 203) and ambient air. As the blades 203 are driven by themotor 202 to suck air into the cooling fan 200, as shown in FIG. 2B,airflow produced by rotation of the blades 203 moves in a directionindicated by arrows in the drawing, including the part of the airflowentering into the cooling fan 200 through a main or central air inlet ofthe frame 201, and the part of the airflow flowing through the outerperiphery of the blades 203, thereby increasing air introduction area ofthe cooling fan 200 and allowing a rate of air intake by rotation of theblades 203 to be enhanced to improve airflow effect.

The distance h for height reduction of the frame 201 of the cooling fan200, with respect to the top of the blades 203, depends on the extent ofimprovement in airflow effect to be achieved. It should be noted that aminimum height of the frame 201 is not smaller than a thickness ofconnecting ribs 204 provided at the bottom of the cooling fan 200, asshown in FIG. 2B. In other words, the frame 201 with the minimum heightis dimensioned equally to the height of the connecting ribs 204 andintegrally formed with the connecting ribs 204.

FIG. 3 illustrates the cooling fan 200 according to a second embodimentof the invention. As shown in the drawing, this cooling fan 200 differsfrom that of the first embodiment (FIG. 2A) in that the frame 201 ofthis cooling fan 200 is provided with a plurality of air-guiding parts205 directly formed at peripheral positions e.g. four corner areas ofthe frame 201. Each of the air-guiding parts 205 is provided with athrough hole 205 a, so as to allow mounting screws (not shown) forconnecting the cooling fan 200 to a heat sink (not shown). Each of theair-guiding parts 205 has its outer peripheral surface being optimallycurve-shaped in compliance with a moving direction of airflow, such thatthrough the rotation of the blades 203 received within the frame 201,air can be quickly and smoothly sucked into the frame 201 along thecurve-shaped outer peripheral surfaces of the air-guiding parts 205 tothereby generate desirable airflow effect and reduce the noise ofvibration during the operation process.

FIG. 4 illustrates the cooling fan 200 according to a third embodimentof the invention. As shown in the drawing, this cooling fan 200 differsfrom that of the second embodiment (FIG. 3) in that, a cover 206 ismounted on the top of the frame 201 to form a housing 20 of this coolingfan 200. The cover 206 is substantially shaped as a flat plate, andformed with a plurality of bars 206 a and openings 206 b in a mannerthat adjacent openings 206 b are spaced by one of the bars 206 a,wherein top surfaces of the bars 206 a may be level with the cover 206or biased by a suitable angle with respect to the cover 206. The cover206 is formed with a plurality of holes 206 f positioned correspondingto the air-guiding parts 205 on the frame 201, such that mounting screws(not shown) can extend through the holes 206 f for connecting the cover206 to the frame 201. Provision of the cover 206 to the frame 201 canenhance structural strength of the cooling fan 200, and the cover 206may serve as a safety shield covering the blades 203 to prevent anoperator from being in contact with and injured by the blades 203 duringrepairing or maintaining a computer.

When the above cooling fan 200 is in use, air sucked by the rotatingblades 203 can enter into the frame 201 via the openings 206 b of thecover 206 and side openings 206 j formed between the cover 206 and theframe 201, thereby increasing air introduction area of the cooling fan200 and improving airflow effect.

FIG. 5A illustrates the cooling fan 200 according to a fourth embodimentof the invention. As shown in the drawing, this cooling fan 200 differsfrom that of the third embodiment (FIG. 4) in that the cover 206 mountedon the frame 201 to form a housing 20 is further provided with aplurality of side plates 206 c that extend from peripheral edges of thecover 206 and are vertically bent downwards. Each of the side plates 206c is formed with a plurality of lateral bars 206 d and lateral openings206 e in a manner that adjacent lateral openings 206 e are spaced by oneof the lateral bars 206 d, wherein the lateral bars 206 d can bearranged horizontally or biased by a suitable angle with respect to theside plates 206 c; such an arrangement can direct air smoothly into theframe 201 of the cooling fan 200. Alternatively, as shown in FIG. 5B,the side plates 206 c of the cover 206 may be formed with a plurality ofvertical bars 206 d and vertical openings 206 e in a manner thatadjacent vertical openings 206 e are spaced by one of the vertical bars206 d, wherein the vertical bars 206 d can be biased by a suitable anglewith respect to the side plates 206 c; such an arrangement can preventdeposition of dust from the upper, thereby reducing dust sucked into thecooling fan 200.

FIG. 6 illustrates the cooling fan 200 according to a fifth embodimentof the invention.

As shown in the drawing, this cooling fan 200 differs from that of thethird embodiment (FIG. 4) in that this cover 206 further includes atleast one grid portion 206 g vertically protruding from peripheral edgesof the flat top portion of the cover 206 downwards, allowing the gridportion 206 g to abut against the frame 201. The grid portion 206 g isformed with a plurality of vertical bars and vertical openings forallowing air to flow through the vertical openings, wherein the verticalbars can be biased by a suitable angle for providing preferable airfloweffect to direct air into the frame 201. The air-guiding parts 205 aredirectly formed on corner areas of the frame 201 for smoothlyintroducing air into the frame 201.

FIG. 7 illustrates the cooling fan 200 according to a sixth embodimentof the invention. As shown in the drawing, this cooling fan 200 differsfrom that of the fourth embodiment (FIG. 5A) in that the cover 206 ismounted on the frame 201 to form a housing 20 and of a frame shapeencompassed by a plurality of ribs 206 i for exposing the blades 203received within the frame 201 to increase air introduction area.Certainly, the ribs 2061 can be arranged vertically or horizontally.

FIG. 8 illustrates the cooling fan 200 according to a seventh embodimentof the invention. As shown in the drawing, this cooling fan 200 differsfrom that of the third embodiment (FIG. 4) in that the cover 206 mountedon the top of the frame of this cooling fan 200 is not formed with aplurality of bars (designated by the reference numeral 206 a in FIG. 4),but has a hollow portion 206 k for receiving the blades 203 therein.Moreover, side openings 206 j (between the cover 206 and the frame 201,as shown in FIG. 4) extend downwardly to the bottom of the frame byremoving a portion of the frame 201 adjacent to the side openings 206 j,making more exposure of the blades 203 to ambient air. In other words,the height of the frame is reduced to the minimum equal to the height ofthe connecting ribs 204 provided at the bottom of the cooling fan 200,allowing the cover 206 to be primarily supported by theperipherally-situated air-guiding parts 205 of the frame. Thisarrangement significantly increases air introduction area of the coolingfan 200, thereby facilitating more air intake into the frame andimproving airflow effect.

The cooling fan 200 of the above embodiments can be fabricated byscrewing the frame 201 and the cover 206 together; alternatively, theframe 201 and the cover 206 may be integrally formed through injectionmolding to form a housing 20.

Therefore, the cooling fan according to the invention can effectivelyincrease air introduction area thereof, and also helps reduce thermalresistance and noise generated during operation of the cooling fan. Itshould be understood that this cooling fan is not limited for use withcomputers, but can be widely adopted in other electronic products withheat dissipating structure.

The invention has been described using exemplary preferred embodiments.However, it is to be understood that the scope of the invention is notlimited to the disclosed embodiments. On the contrary, it is intended tocover various modifications and similar arrangements. The scope of theclaims, therefore, should be accorded the broadest interpretation so asto encompass all such modifications and similar arrangements.

1. A cooling fan, comprising: a plurality of blades; a frame forreceiving the blades; and a cover formed on the frame, and comprising atleast one side plate, wherein the at least one side plate is formed witha plurality of bars such that at least one lateral air intake is formedbetween the bars; wherein the plurality of bars are biased by an angleto direct air into the cover, and the frame and the cover are formed asa single piece.
 2. The cooling fan of claim 1, wherein the cover furthercomprises a top portion being formed with a plurality of bars andopenings in a manner that adjacent openings are spaced by one of thebars.
 3. The cooling fan of claim 2, wherein top surfaces of the bars ofthe top portion are biased by a predetermined angle, with respect to thetop portion of the cover, and not perpendicular to the top portion. 4.The cooling fan of claim 1, wherein the cover further comprises a topportion, and the at least one side plate is extended from at least oneperipheral edge of the top portion and bent vertically downwards.
 5. Thecooling fan of claim 1, wherein the frame and the cover are integrallyformed through injection molding.
 6. The cooling fan of claim 1, whereinthe frame further includes a plurality of ribs formed on a bottomportion of the frame for supporting the blades and strengthening thecooling fan.
 7. A cooling fan, comprising: a plurality of blades; and amolded housing for receiving the blade therein, comprising: a pluralityof bars formed on at least one side portion of the molded housing suchthat at least one lateral air intake is formed between the bars, whereinthe plurality of bars are biased by an angle to direct air to flow intothe molded housing.
 8. The cooling fan of claim 7, wherein the moldedhousing further comprises a top portion being formed with a plurality ofbars and openings in a manner that adjacent openings are spaced by oneof the bars.
 9. The cooling fan of claim 8, wherein top surfaces of thebars of the top portion are biased by a predetermined angle with respectto the top portion of the molded housing, and not perpendicular to thetop portion.
 10. The cooling fan of claim 7, wherein the molded housingfurther comprises a top portion, and the at least one side portion isextended from at least one peripheral edge of the top portion and bentvertically downwards.
 11. The cooling fan of claim 7, wherein the moldedhousing is formed through injection molding.
 12. The cooling fan ofclaim 7, wherein the molded housing further includes a plurality of ribsformed on a bottom portion of the molded housing for supporting theblades and strengthening the cooling fan.